Lay-in closure for lighting fixture



Dec. 12; 1967 w. 'J. TRANTINA 3,358,138

LAYIN CLOSURE FOR LIGHTING FIXTURE Filed Dec. 13. 1965 2 Sheets-Sheet 1 i mu/z/vra? L WALTER .J. TQAA/T/NA Dec. 12, 1967v w. J. TRANTINA LAY'IN CLOSURE FOR LIGHTING FIXTURE 2 Sheets-Sheet 2 Filed Dec. 13, 1965 IIIIIII A @W n 3; W #J. Q i m m United States Patent 3,358,138 LAY-IN CLOSURE FOR LIGHTING FIXTURE Walter J. Tranfina, St. Louis County, Mo., assignor to Emerson Electric Co., St. Louis, Mo., a corporation of Missouri Filed Dec. 13, 1965, Ser. No. 513,303 5 Claims. (Cl. 240147) ABSTRACT OF THE DISCLQSURE In a lighting fixture with a lay-in type closure, having a fixed frame with side walls and end walls and inwardly projecting flanges, a diffuser having sides and ends and a hinge lug projecting from each end over the end flanges of the frame, a tab projecting inwardly from each of the end Walls above the end wall flange and spaced from its adjacent side wall a distance greater than the distance of the hinge lug from the side of the diffuser nearest them and a housing wall overhanging the end flange adjacent the tab and spaced from the top of the tab, at a point between the tab and the side wall closer to the tab than the height of the adjacent side of the diffuser, a distance greater than the effective thickness of the hinge lug but less than the distance of the hinge lug from the side of the diffuser nearest it. This arrangement precludes accidental dislodgement of the diffuser in both laid in and swung down positions.

Background of the invention This invention relates to lay-in closures for lighting fixtures.

One of the objects of this invention is to provide a lay-in closure for lighting fixtures which may be installed easily and can be deliberately swung down or removed readily, but which cannot, for all practical purposes, be dislodged accidentally.

Other objects will become apparent to those skilled in the art in the light of the following description and accompanying drawings.

Summary of the invention In accordance with this invention, generally stated, a lay-in type lighting fixture closure is employed with a fixture body having side walls containing the usual parallel side flanges and end walls having end flanges perpendicular to the side flanges. The closure hereafter called a diffuser has sides and ends, being of a width to over-lie and rest upon the side flanges and of a length to end short of the end flanges when it is in its normal light-diffusing position. The diffuser has a hinge lug projecting from each of its ends and extending over the fixture end flanges, the hinge lugs being spaced from but near one side of the diffuser. A lamp housing, of which the fixed frame is a part, extends above the flanges and the diffuser. Broadly, all of these elements are common to lighting fixtures with lay-in diffusers. In the fixture of this invention tab members are provided, projecting inboardly from each of the end walls above the end wall flange and spaced from the side wall a distance greater than the distance of the hinge lugs from the side of the diffuser nearest them. A housing Wall is provided which over-hangs the end flange adjacent the tab and is spaced from it a distance greater than the effective thickness of the hinge lug but less than the distance of the hinge lugs from the side of the diffuser nearest them. Preferably, two tabs are provided on each end, to permit mounting of the diffuser at either side. Also, preferably the side walls are provided with stop ears, projecting part way across the side flanges, and of a height less than the height of the tab members.

In the preferred embodiment, the side wall ears make it necessary to raise the diffuser vertically as well as to shift it transversely, in order to permit the diffuser to clear the side flange away from which it swings down. The arrangement of the end wall tabs and over-hanging housing wall is such as to make it necessary to raise the diffuser after it has cleared the side wall flange to swing down, to hold the diffuser at a high angle and to translate the diffuser while it is so held, in order to remove the diffuser from the frame. This ensures against accidental removal. At the same time, the maneuver by which the diffuser is deliberately removed is well within the capabilities of anyone charged with their maintenance.

Brief description 0 the drawing In the drawing:

FIGURE 1 is a view in perspective, looking up, of one illustrative embodiment of lighting fixture of this invention, mounted in a ceiling;

FIGURE 2 is a sectional view taken along the line 22 of FIGURE 1;

FIGURE 3 is a sectional view taken along the line 33 of FIGURE 1;

FIGURE 4- is a sectional view taken along the line 44 of FIGURE 3;

FIGURE 5 is a fragmentary sectional view taken on the line 5-5 of FIGURE 4;

FIGURE 6 is a fragmentary view in perspective, partly in section, showing a corner of a frame constituting a part of a diffuser of this invention;

FIGURE 7 is a view in perspective of a part of the frame shown in FIGURE 6, without the light-permeable panel, with one frame member removed to show a corner angle member with an integral hinge lug; and

FIGURE 8 is a view in perspective, partly in section, of an end frame member of a so-called frameless diffuser panel, showing an integral hinge lug.

Description of the preferred embodiments Referring now to the drawings for one illustrative embodiment of a lighting fixture with lay-in diffuser of this ,edges, vertical ribs 13, projecting above the upper surface 12. Along the short sides of the panel 10, between the ribs 13, where the panel is bounded by its upper and lower surfaces 12 and 11, frame members 15 are mounted. The end frame members 15 have inboardly extending spaced panel flanges 16, defining between them a panel-mounting channel into which the short edge of the panel, between the ribs 13, fits. The frame member 15 extends through the full length of the end edges between the ribs 13, and has a back 17 with an inboard surface of which the flanges 16 are integral, and with the outboard, vertical, flat surface of which, a hinge lug 20 is integral. A locating lug 25 is integral with the under side of the lower flange 16.

Thefixed frame assembly 30 includes two, parallel, oppositely disposed, long side members 35, and two, parallel, short end members 45, arranged perpendicularly to the long side members 35, as illustrated in FIGURE 4. As has been explained above, the fixed frame assembly 30 forms a part of the complete lamp housing 60.

In the illustrative embodiment shown, each long side member 35 is a one piece extrusion, with a vertical side wall 36, an inboardly extending horizontal top wall 37, an inboardly extending lower diffuser supporting flange 38, and an outboardly extending casing flange 39. Stop ears 40, preferably at least two in number, are lanced from the vertical side wall 35, and project part way across the width of the flange 38.

In this embodiment, each short end member 45 has a vertical wall 46, along the upper edge of which is an offset upstanding rim 47, and along the lower edge of which is a channel-defining molding consisting of an inboardly extending bottom wall 43 and an inboard vertical wall 49, defining, with the lower part of the wail 46, a channel 50. A gasket 51, of the type described in my copending application Ser. No. 513,304 filed concurrently with the present application, is mounted in the channel 50. The end members 45 can be and preferably are of the type described in that application.

An inverted T-shaped rail 52 has a stem 53 which is fastened against the outside surface of the vertical wall 46, and a cross head 54 which forms a casing flange both for the molding and for the ceiling margins.

A tab 55, lanced from the side wall 46, projects at least part way across the channel and gasket 51. A lower edge 56 of the tab 55 brushes the top surface of the gasket 51. An upper edge 57 of the tab 55 is spaced below the upper wall 37 of the fixed frame 30 a distance greater than the effective thickness of the hinge lug 2t and less than the distance between the outboard edge of the rib 13 and the far edge of the lug 29 with respect to the rib.

The tabs 55 and stop ears 40 are spaced from one another with respect to the length of the end wall farther than the distance from the inboard side of the hinge lugs to the nearest side of the diffuser, and less than the combined distance from the inboard side of the hinge lugs to the nearest side of the diffuser and the over-hang of the opposite side edge of the diffuser in place.

The lamp encompassing portion of the lamp housing 60 includes reflecting top walls 61, side walls 62, and end walls 63. Lamp sockets 64, mounted against the end walls 63, carry lamps 65. Integral with and extending outboardly from the lower edge of the side walls 62, are over-hanging housing wings 67, mounted on and constituting in effect inboard extensions of the walls 37 of the fixed frame 30. The lower edge of each of the end walls 63 is off-set inwardly to form a depending rim 74, complementary to the off-set rim 47 of the end walls 45 of the fixed frame. The rims 47 and 74 mate as shown particularly in FIGURE 2.

In operation, the diffuser is mounted in the fixed frame by inserting it diagonally and raising the hinge lug side sufliciently to permit the hinge lugs 20 to clear the end walls 49. It is then straightened to permit the diffuser to be swung up and lifted at the same time to the position shown in FIGURE 5, when the hinge lugs 20 will clear the upper edge 57 of the tabs 55. The diffuser is then swung up slightly more, and shifted toward the side wall 36 as viewed in FIGURE 5, over the top of the stop ears 40, until the other long side edge of the diffuser has cleared the flange 38 on the opposite side of the frame 39. The diffuser is then raised to the position at which it is entirely above the flanges 38, and shifted away from the wall 36 as viewed in FIGURE 5 until its edge clears the ears 40. It is then dropped to the position shown in full lines in FIGURE 3. In this position, the locating lugs 25 are closely adjacent but inboard of the flanges 38 on both sides.

For purposes of maintenance, the diffuser can be swung down by lifting the diffuser straight up until the lower surface of the diffuser is above the tabs 40, shifting the diffuser toward the wall 36 as viewed in FIGURES 3 and 5, until the opposite edge of the diffuser clears the flange 38 on which it was resting, when it can be lowered to the position shown in dotted lines in FIGURE 3, where it is held by the bearing of the hinge lugs 20 on the top of the gasket 51.

The diffuser 3 has been described in terms of a so-called frameless diffuser. In FIGURES 6 and 7, a frame type diffuser is illustrated, in which extruded frame members extend around the four edges of a plane panel 81. The frame members 30 are joined at the corners of the panel by means of corner angles 83, two of which have hinge lugs integral with them, and two of which do not. The hinge lugs 85, like the hinge lugs 20, are aligned axially near and at opposite ends of one long side of the panel. In this embodiment of diffuser, the frame members 80 are provided with a locating ledge 36, running the full length of the frame members, instead of the locating lugs 25. 'However, the function of the ledge and lugs is the same, to provide an easy way to determine that the diffuser has been properly seated in the fixture frame.

It can be seen that the provision of tabs 55 at each side of the fixture permits the installation of the diffuser from either side, and does not interfere with its operation in any respect.

Numerous variations in the construction of the fixture of this invention, within the scope of the appended claims, will occur to those skilled in the art in the light of the foregoing disclosure.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. In a lighting fixture with a lay-in type closure having a fixed frame with side walls having parallel side flanges and end walls having parallel end flanges perpendicular to said side flanges, a diffuser having sides and ends, said diffuser being a width to overlie and rest upon said side flanges and a length to end short of said end flanges when in its light-diffusing condition, said diffuser having a hinge lug projecting from each end over the said end flanges, said hinge lugs being spaced from but near one side of said diffuser, and a lamp housing above said flanges and diffuser, the improvement comprising a tab member projecting inboardly from each of said end walls above the end wall flange and spaced from said side wall a distance greater than the distance of the hinge lugs from the side of the diffuser nearest them, and a housing wall over-hanging the end flange adjacent the said tab and spaced from the top of said tab at a point between the tab and the side wall closer to said tab than the height of the adjacent side of the diffuser a distance: greater than the effective thickness of the hinge lug but less than the distance of the hinge lug from the side of the diffuser nearest it.

2. The improvement of claim 1 wherein a tab member projects inboardly from said end walls at both sides of the fixed frame.

3. The improvement of claim 1 wherein stop ears project inboardly from the side walls a distance laterally outboardly from the said tabs greater than the distance from the inboard side of the hinge lugs to the nearest side of the diffuser and less than the combined distance from the inboard side of the hinge lugs to the nearest side of the diffuser and the overhang of the opposite side edge of References Cited the diifuser in place over the side iiange, said stop ears UNITED STATES PATENTS being spaced below the over-hanging housing wall a 2 978 575 961 Cob 240 78 (1'1: tth th 1ft h'ht thd'if t en gm er an e e we e 1 user a 5 3,158,330 11/1964 Van Steenhoven 24o -7s 4. The improvement of claim 3 wherein the stops ears 3'281588 10/1966 Spmetta 240 147 XR are lanced mm the slde Walls' NORTON ANSHER, Primary Examiner.

5. The improvement of claim 1 wherein the tabs are lan ed f th d ll D. L. JACOBSON, Assistant Examiner. 

1. IN A LIGHTING FIXTURE WITH A LAY-IN TYPE CLOSURE HAVING A FIXED FRAME WITH SIDE WALLS HAVING PARALLEL SIDE FLANGES AND END WALLS HAVING PARALLEL END FLANGES PERPENCIRCULAR TO SAID SIDE FLANGES, A DIFFUSER HAVING SIDES AND ENDS, SAID DIFFUSER BEING A WIDTH TO OVERLIE AND REST UPON SAID SIDE FLANGES AND A LENGTH TO END SHORT OF SAID END FLANGES WHEN IN ITS LIGHT-DIFFUSING CONDITION, SAID DIFFUSER HAVING A HINGE LUG PROJECTING FROM EACH END OVER THE SAID END FLANGES, SAID HINGE LUGS BEING SPACED FROM BUT NEAR ONE SIDE OF SAID DIFFUSER, AND A LAMP HOUSING ABOVE SAID FLANGES AND DIFFUSER, THE IMPROVEMENT COMPRISING A TAB MEMBER PROJECTING INBOARDLY FROM EACH OF SAID END WALL ABOVE THE END WALL FLANGE AND SPACED FROM SAID SIDE WALL A DISTANCE GREATER THAN THE DISTANCE OF THE HINGE LUGS FROM THE SIDE OF THE DIFFUSER NEAREST THEM, AND A HOUSING WALL OVERHANGING THE END FLANGE ADJACENT THE SAID TAB AND SPACED FROM THE TOP OF SAID TAB AT A POINT BETWEEN THE TAB AND THE SIDE WALL CLOSER TO SAID TAB THAN THE HEIGHT OF THE ADJACENT SIDE OF THE DIFFUSER A DISTANCE GREATER THAN THE EFFECTIVE THICKNESS OF THE HINGE LUG BUT LESS THAN THE DISTANCE OF THE HINGE LUG FROM THE SIDE OF THE DIFFUSER NEAREST IT. 